Rod welding apparatus for making threaded drill rods

ABSTRACT

Rod welding apparatus that includes a rod positioner and a chuck assembly mounted on opposite ends of a frame for movement toward and away from one another, a plurality of roller assemblies intermediate the first mentioned assemblies for supporting a pair of rod portions with a threaded together pin and box combination intermediate the rod portions, a hold down assembly having driven rollers to releasably hold the rod portions down on the roller assemblies and rotate the rod portions and said combination while the rod portions and combination are held in axial compression by the first mentioned assemblies, a welder machine, a seam locator unit and controls for welding the pin to one rod portion and the box to the other rod portion, and a linear travel assembly for moving the rod portion adjacent the rod positioner assembly toward the chuck assembly, and the method of welding the rod portions together.

,[22] Filed:

United States Patent [1 1 Ronnkvist .1 ROD WELDING APPARATUS FOR MAKINGTHREADED DRILL RODS [75] Inventor: Ake E. Ronnkvist, Excelsior, Minn.

[73] Assignee: E. J. Longyear Company, Minneapolis, Minn.

Oct. 26, 1970 [21] Appl. No.: 83,899

[52] US. Cl. ..228/6, 29/464, 29/484,

214/1 P, 219/59, 228/9, 228/45, 228/48 [51] Int. Cl. ..B23k 5/00 [58]Field of Search ..219/60 A, 85, 59,

219/60; 214/25, 1 P; 113/116 UT, 116 DD; 29/464, 484; 228/4, 15, 17, 45,48, 25, 9

[ Apr. 10, 1973 Primary Examiner.l. Spencer Overholser AssistantExaminer-Robert J. Craig Azt0meyDugger, Peterson, Johnson & Westman [57]ABSTRACT Rod welding apparatus that includes a rod positioner and achuck assembly mounted on opposite ends of a frame for movement towardand away from one another, a plurality of roller assemblies intermediatethe first mentioned assemblies for supporting a pair of rod portionswith a threaded together pin and box combination intermediate the rodportions, a hold down assembly having driven rollers to releasably holdthe rod portions down on the roller assemblies and rotate the rodportions and said combination while the rod portions and combination areheld in axial compression by the first mentioned assemblies, a weldermachine, a seam locator unit and controls for welding the pin to one rodportion and the box to the other rod portion, and a linear travelassembly for moving the rod portion adjacent the rod positioner assemblytoward the chuck assembly, and the method of welding the rod portionstogether.

32 Claims, 14 Drawing Figures ROD WELDING APPARATUS FOR MAKING THREADEDDRILL RODS The chuck disclosed in this application is more fullydisclosed in the copending application, Ser. No. 81,697, tiled Oct. 19,1970, now US. Pat. No. 3,692,320, of Leonard A. Lindelof and Albert L.Linn and entitled Chuck Apparatus" while the drill rod formed isdisclosed in the application of John F. Hoffmeister entitled CompositeRods which is Ser. No. 84,001, tiled the same day as this applicationthis latter application being commonly assigned to the assignee of thisapplication.

BACKGROUND OF THE INVENTION This invention relates to rod weldingapparatus for supporting rod portions in axial alignment with a pin andbox combination and welding the pin to one rod portion and the box toanother rod portion. In the prior art it is old to machine an integrallyformed 'rod blank to provide a pin portion on one end and a box portionon the other end. However, in order to have the pin and box portions ofadequate strength, the rodblank is more expensive than necessary andrequires a higher quality steel for the major portion of the length ofthe rod than is necessary. In order to overcome problems of the abovementioned nature, as well as providing a method and apparatus for makingdrill rods from separately processed pin, box and intermediate rodportions, and overcoming other problems, this invention has been made.

SUMMARY OF THE INVENTION The invention includes rod welding apparatushaving a cradle assembly for supporting rod portions, a pin and a box inaxial alignment, reciprocally movable rod positioner and chuckassemblies for holding the rod portions, pin and box in axialcompression, a rod hold down assembly for releasably holding the rodportions down on the cradle assembly, and a welding machine for weldinga pin and a box to opposite ends of a rod portion.

One of the objects of this invention is to provide new and novelapparatus for welding a pin and a box to opposite ends of a rod portionand a novel method for doing so. In furtherance of the above mentionedobject, it isa further object of this invention to provide new and novelapparatus to retain a pin and box in axial alignment with rod portionsand welding the pin and box to the rod portions while rotating the pin,box and rod portions. I

Another object of this invention is to provide new and novel apparatusand method for holding rod portions and a threaded together pin and boxcombination in axial compression with said combination between the rodportions while welding the pin to one rod portion and the box to theother rod portion and thence unthreading the threaded connection betweenthe pin and box.ln furtherance of the above mentioned object,

, it is another object of this invention to provide new and combination,and that the pin and box each have tapered surfaces at theirnon-threaded ends that are at least in part of an opposite taper fromthat of surfaces of the ends of the rod portions to which they are to bewelded to, such as more fully described in the above mentionedapplication entitled Composite Rods.

BRIEF DESCRIPTION OF THE DRAWINGS lines in a rod compress position;

FIG. 4 is a transverse cross sectional view generally takenalong theline and in the direction of arrows 4-4 of FIG. 2, said view showing therod hold down assembly in a rod hold down position in solid lines and inan elevated rod release position in dotted lines;

FIG. 5 is a fragmentary enlarged transverse cross sectional viewgenerally taken along the line and in the direction of arrows 55 of FIG.2 to more clearly illustrate the linear travel and rod clamp assembly;

FIG. 6 is an enlarged fragmentary transverse cross sectional viewgenerally taken along the line and in the direction of the arrows 6-6 ofFIG. 2 to more clearly illustrate the mounting of the cradle rollersthat are adjacent the rod clamp assembly;

FIG. 7 is an enlarged side view of the chuck travel assembly, theportion of the view of the chuck mechanism shown in cross section beinggenerally taken along the line and in the direction of the arrows 77 ofFIG. 8;

FIG. 8 is an end view of the chuck travel assembly, said view beinggenerally taken along the line and in the direction of the arrows 8-8 ofFIG. 7;

FIG. 9 is in part a schematic showing of a seam locator unit, a welderhead unit mounted on the locator unit, and an illustration of a threadedtogether pin and box combination between parts of rod portions that areto be welded thereto;

FIG. 10 is a transverse schematic showing of the units of FIG. 9, a postwelding heater and a drill stem rod part; v

FIG. 11 is a fragmentary enlarged view of the adjacent parts of rodportions, pin and box of FIG. 9 in positions to have the pin welded toone rod portion and the box to the other rod portion;

FIG. 12 is a fragmentary plan view of the control mechanism foroperating limit switches that in part control the start and stop of thewelding;

FIG. 13 is a schematic showing of the hydraulic circuitry and componentsof the apparatus of this invention; and

FIG. 14 is a schematic showing of the electric circuitry and componentsof the control mechanism.

Referring now in particular to FIG. 1, the apparatus of this inventionincludes a longitudinally elongated frame, generally designated 11, arod positioner assembly, generally designated 12, mounted at the forwardend portion of the frame; a chuck travel assembly,

generally designated 15, mounted on the rearward end portion of theframe; a cradle assembly, generally designated 13, mounted on the frameintermediate assemblies 12 and 15; a rod hold down assembly, generallydesignated 18, mounted on the longitudinally intermediate portion of theframe; a linear travel and rod clamp assembly, generally designated 14,mounted on the frame beneath the rod hold down assembly; a

1 rod welder machine, generally designated 16, mounted being mounted ona plurality of spaced uprights 28.

Mounted on the channels 24, to extend the length thereof is a mountingplate 29, the edge of the mounting plate opposite channel 24 beingwelded to a longitudinally elongated channel 27. Also,-one longitudinaledge of a support plate is welded to channel 27 while the opposite edgeis attached to'channel 26. It is being shown in FIG. 1, as well asadditional roller assemblies R. Since each of the aforementioned rollerassemblies is of the same construction as the roller assembly Rillustrated in FIG. 4, the roller assemblies will be described withreference to the roller assembly illustrated in FIG. 3 and the rollerassembly illustrated in FIG. 4. Each roller assembly R includes a base52 secured to the plate 29, longitudinally spaced uprights 53, 56 thatare mounted by the base 52, transversely spaced shafts 54, 57 havingtheir one ends mounted by upright 53 and their opposite ends mounted byupright to be understood that each of the above mentioned channels andplates may be made up of a plurality of members having adjacent endsjoined together.

The rod positioner assembly 12 includes a longitudinally elongated,horizontal plate 32 bolted to the forward end portion of plate 29 toextend forwardly thereof (see FIG. 3). A pair of longitudinallyelongated, transversely spaced slide shafts 33 have their end portionsmounted by shaft supports 34 which in turn are mounted by plate 32 tosupport the shafts vertically spaced above said plate 32. The generallyrectangular base 36 of a live center assembly has each of its cornerportions attached to base side members 37, two of the base slide membersbeing mounted on one of the shafts 33 and the other two being mounted onthe other shaft 33. A support member 38 is bolted to the base 36 forrotatably mounting a longitudinally extending shaft 39 a substantialdistance vertically above base 36. The .rearend of shaftx39 mounts agenerally frusto-conical live cente r member 40 having a minor baseextending rearwardly of said shaft and support member 38, the forwardendof the shaft having a sprocket 551 keyed thereto.

A vertical bar 43 is dependingly secured to the central portion of base36, the lower end of the bar mounting the transverse pivot member 44which in turn pivotally mounts the one end of the piston rod 45 of thepiston cylinder combination 46. The. aforementioned piston cylindercombination includes a cylinder 46 that has its intermediate portionmounted by a transverse pivot member 47. Pivot member 47 is mounted by apair of longitudinally extending brackets 48 (one on either side of thecylinder) that are dependingly secured to plate 29. Both plates 29 and32 have longitudinally elongated slots (not shown) to permit the barbeing moved therethrough throughout the length of the piston rod stroke.

The cradle assembly 13 includes a pair of roller assemblies R mountedintermediate the positioner assembly and the rod hold down assembly, oneof said roller assemblies being shown in FIG. 3 and the other 56, aroller 55 rotatably mounted on shaft 54 and a roller 58 rotatablymounted on shaft 57. The shafts 54,

57 are mounted at the same elevation while the rollers are of the samediameters, of substantially larger diameters than the rod portion to besupported thereby, and are mounted such that, as viewed in FIG. 4, theyin part transversely overlap one another, but are longitudinallyadjacent one another. Thus, the rollers provide a nip for rotatablysupporting a rod portion and resist transverse movement of the rodportion. The rollers 55, 58 support a rod portion at an elevation thatthe axis of rotation of the rod portion is aligned with the center ofthe frusto-conical portion of the live center member 40.

Referring now to FIGS. 2 and 4, the rod hold down assembly 18 includes apair of uprights 62 mounted on plate 30 above frame member 26, eachupright mounting a longitudinal, horizontal pivot member 63 which inturn pivotally mounts a bracket 64. Each bracket mounts the adjacent endof a longitudinal channel 65, the one ends of a pairof spaced transversechannels 67 being secured to the adjacent ends of the channel 65. Theopposite ends of the channels 67 mounts a longitudinal channel 66. Tothe transverse intermediate portion of each channel 67 there isdependingly mounted a bracket 68, the piston rod 69 of a piston cylindercombination 69, 70 being pivotally connected by a transverse pivotmember 71 to the respective bracket 68. Each of the aforementionedpiston cylinder. combinations includes a cylinder 70 that is pivotallyconnected by a transverse pivot member 72- toa bracket73 that in turnis-mounted by plate 30.

Each end of the channel 66 dependingly mounts-a bearing member 76 whichin turn rotatably mounts a shaft 77 to extend parallel to said channel.On the shaft,

intermediate the bearing members 76, there is keyeda plurality ofaxially spaced rollers 78. In the assembly 18 rod hold down position,each roller 78 is located directly above a roller assembly R to have thelowermost portion of the roller 78 located directly above the nip formedby rollers 55, 58. The uppermost circumferentialportion of each roller78 bears against a pair of transversely spaced rollers 80 that arerotatably mounted by a clevis bracket 81 for rotation about alongitudinal axis. Each bracket 81 is dependingly mounted by the channel66. Rollers 80 prevent the adjacent roller 78 from being moved to adifferent elevation than the axially adjacent rollers 78 as a result ofshaft 77 bowing if rollers 80 were not provided.

On the forward end of shaft 77 there is keyed a sprocket 82, a chain 83beingextended around sprocket 82 and sprocket 84 to impart a'drivingrotary motion to the shaft. Sprocket 84 is keyed to the motor I shaft ofthe hydraulic motor 85 which in tumvis dependingly mounted from thefront channel 67 by a bracket 86.

Referring to FIGS. 1, 2 and 5, longitudinally intermediate the length ofchannel 66, the linear travel and rod clamp assembly 14 is mounted byplate 29. Assembly 14 includes a generally U-shaped bracket having a webportion 90 located at a lower elevation than plate 29 and transverselyspaced legs 91 having their lower ends joined to the web portion toextend upwardly through an appropriate aperture in plate 29 to asubstantially-higher elevation than said'plate. Tabs 89 are welded tolegs 91 and are bolted to plate 29 to hold bracket 90, 91, 91 in a fixedposition. The upper ends of the legs mount bearing members 92 which inturn rotatably support the transverse shaft extension 93 that is coupledat 94 to the motor shaft 95 of the hydraulic motor 96. The motor 96 ismounted on the bracket 97 which in turn is mounted by adjacent leg 91.Keyed to the shaft extension 93 intermediate bearing members 92 is aroller 98, roller 98 being of a minimum diameter intermediate itsopposite axial ends and being of progressively increasing diameterstoward the ends thereof to provide a concave circumferential surfacesuch as shown in FIG. 5.

Dependingly mounted by web 90 in a fixed position is a cylinder 102 of avertical piston cylinder combination 102, 103. The piston rod 103 of theaforementioned combination is slidably extended through an appropriatecentral aperture in the web 90 and at its upper end mounts a clevisbracket 104. Each leg portion of the bracket 104 mounts a roller (notshown) that extends into the vertical groove (not shown) of the adjacentleg 91. The aforementioned guides, and the rollers that are rotatablymounted in the guides, insure that the bracket 104 moves in a verticaldirection as the piston rod 103 is reciprocated between its extendedposition of FIG. 5 and it retracted position. The upper ends of the legsof the bracket 104 mount a roller 106 for rotation about a transverseaxis, the roller 106 having two frusto-conical half portions that. arejoined together at their minor bases. It is to be noted that the axis ofrotation of roller 106 is directly beneath-and parallel to the axis ofrotation of roller 98; the spacing of roller 98 and roller 106 in itsmaximum elevation being such to clamp a rod therebetween to prevent therod being moved either axially, transversely or being rotated. Theminimum diameter parts of rollers 98,106

are located in a vertical plane that passes through the nips of rollers55, 58.

Referring now to FIGS. 7 and 8, the chuck travel assembly 15 includes apair of transversely spaced, longitudinally extending guide rods 116,each end of each guide rod being mounted by a bracket 115. The frontbrackets are mounted by a transverse support 114 while the rear bracketsare mounted by a second support 114. The supports 114 are mounted byplate 29. Mounted for slidable movement by rods 116 are slide rings 113which in turn mount the base 117. The base mounts a vertical bar 118that extends through a longitudinally elongated slot 125 provided inplate 29. The lower end of the bar is pivotally connected at 124 to thepiston rod 1 19 of the piston cylinder combination 119,

.120. The intermediate portion of the cylinder 120 of the aforementionedcombination is mounted for pendingly secured to the front support 1 14that has opposite ends mounted by plate 29 on opposite sides of slot125.

Support members 128 which are mounted on the base 117 mount housingmounting mechanism 127 which in turn mounts a generally annular housing129 having a central longitudinal axis aligned with the axis of rotationof live center member 40. The housing at its rear end is secured to andextends through an aperture in a vertical, transverse support plate 130while the opposite end of the housing opens to the hydraulic chuckannular piston 153. The piston 153 and housing have adjacent flangeportions that are bolted together whereby the chuck is mounted by thehousing. The housing mounts bearing members 136 which in turn rotatablymounts the rod drive tube 135. Within tube there is mounted a livecenter tube 137 to rotate therewith, tube 135 mounting bearings 138 thatin turn mount the idler tube 139 for rotation relative tube 135. Theforward end portion of tube 139 mounts a generally frustoconical coneidler (live centermember) 140 to rotate with tube 139, the idlerextending axially into the center opening of the annular piston 153.

The live center tube 137 and rod drive tube 135 are keyed together, asprocket member 142 being clamped to the rear end portion of the livecenter tube for driving the live center tube. Sprocket 142 is driven bya smaller diameter sprocket 143 which is keyed to the motor shaft 145 ofthehydraulic motor 144, the motor being mounted on the upper end portionof support plate 130 and having its shaft rotatably extendedtherethrough.

Even though the chuck 133 illustrated in the drawings does not per seform a part of this invention, it will be briefly described in order tomore readily facilitate the understanding of this invention. The chuckincludes the aforementioned annular piston 153 which slidably extendsinto the annular chamber of the cylinder 148, a bearing being mounted bythe cylinder and the annular thrust plate 149 to permit relativerotation between the bearing and thrust plate. A chuck hood 150 ismounted by a chuck body 151, the chuck body in turn having an endportion mounted by the rod drive tube to rotate therewith. The chuckbody mounts a plurality of circumferentially jaws 152 for slidablyradial movement, the jaws being retained in a rod clamping position bythe chuck body when the piston 153 and cylinder 148 are in theirrelative retracted positions as shown in FIG. 7. Resilient means (notshown) are mounted by the chuck body and chuck move and are resilientlymoved radially outwardly from a rod clamping position; the chuck hoodbeing resiliently returned to the FIG. 7 position through the action ofthe resilient means (not shown) upon the pressurized fluid in thecylinder being permitted to exhaust therefrom.

Through the structure above described, the chuck body and chuck hood arefree to rotate relative the piston 153 and cylinder 148 and the housing129; but at the same time are mounted to be moved axially by thehousing. In this connection, the chuck body is mounted to be in a fixedaxial position relative the housing as long as the housing is rotated inthe appropriate direction.

Mounted longitudinally intermediate the roller assemblies mountedbeneath the rod hold down assembly and the chuck travel assembly are oneor more roller assemblies R.

Mounted directly beneath the longitudinally central portion of channel66 in its rod clamp, position is a roller assembly, generally designatedT (see FlGs. 2 and 6). The roller assembly T includes a base plate 158abutting against plate 29 and bolted to channels 24, 25, and ahorizontal support plate 159 that is vertically slidably mounted onbolts 160 that have nuts threaded thereon to limit the upper movement ofthe support plate relative the base plate. The bolts 160 are secured inthe base plate, there being provided coil springs 161 on the boltsintermediate plates 158, 159 for resiliently urging plate 159 in anupward direction. A pair of shaft supports 162 are mounted on onetransverse side portion of the base plate to mount a shaft 163, aplurality of spaced rollers 166 being rotatably mounted on said shaft.On the opposite transverse portion of the base plate there is mounted asecond pair of shaft supports 165 which in turn mounts a shaft 164;shaft 164 rotatably mounting a plurality of longitudinally spacedrollers 167. The rollers on shaft 163 are longitudinally offset from therollers on shaft 164 with the rollers on the respective shafts beingtransversely close enough together to form a nip for supporting a rodportion such as described with reference to roller assemblies R.

On either longitudinal side of the roller assembly T there is provided aroller assembly R while forwardly of the forward one of the lastmentioned roller assemblies R there is mounted the linear travel and rodclamp assembly 14. Just forwardly of the assembly 14 there is provided asecond roller assembly, generally designated S which is of the sameconstruction as roller assembly T Referring now to FIG. 14, theelectrical control circuitry and components, generally designated 175,in-

cludes mainlines M and M, on which there is respectively providedjunctions 177 and 182. Connected across junctions 177, 178 is a masterON-OFF switch 176 that is resiliently retained in an open position. Anormally closed stop switch 181 and the solenoid coil 179 of a relay 180are connected in series across junctions 178, 182. Relay 180 includes afirst terminal 183 that is connected by a line to junction 177, a secondterminal 185 connected by a line to junction 190, a switch member 186, athird terminal 188 connected to line L,, a fourth terminal 187 connectedto junction 182 and a switch member 189. When the relay is energized,switch member 186 moves to electrically connect terminals 183, 185; andswitch member 189 moves to electrically connect terminals 187, 188.

Junction 190 is connected by lines to junctions 178, while a manuallyoperated ON-OFF switch 191, which remains in the position it is switchedto, is connected across junction 190 and main line L On main line Lthere is provided junctions 196-204, while on line L there is providedjunctions 205-218. The motor 427 (or appropriate motor starter circuitryfor energizing the motor) is connected across junctions 190, 233 while aswitch 222 that is resiliently retained in an open position is connectedacross junctions 223, 224. The coil 228 of relay 229 and a stop switch227 resiliently retained in a closed position are connected in seriesacross junctions 205, 224. The relay 229 has a terminal 231 connected tojunction 224, a terminal 230 connected to junction 233 and a switchmember 232 that electrically connects terminals 230, 231 when coil 228is energized.

A limit switch 236 has a first terminal 251 connected to junction 196, asecond terminal 252 connected to junction 237, a third terminal 253connected to junction 255 and a switch member 254 resiliently retainedin a position connecting terminals 251, 252 but movable to connectedterminals 251, 253.

Junction 237 is connected by a line to a first terminal 238 of amanually operated switch 239. Switch 239 includes a second terminal 240connected to junction 241, a third terminal 243, a fourth terminal 244,a fifth terrninal 245 connected by a line to junction 237, a sixthterminal 246 connected by a line to junction 248, a switch member 242and a switch member 247. Switch 239 is the type that its switch membersremain in a given position until switched to the second position. In afirst position, switch member 247 forms an electrical connection betweenterminals 243, 244 while switch member 242 does not form an electricalconnection between any of the terminals of switch 239. In the secondposition, switch member 242 electrically connects terminals 238, 240while switch member 247 breaks the electrical connection betweenterminals 243, 244 and electrically connects terminals 245, 246. A limitswitch 257 that is resiliently retained in an open position is connectedacross junction 197 and terminal 243.

A relay 260 has a first terminal 261 connected by a line to junction241, a second terminal 262 connected by a line to junction 237, a thirdterminal 263 connected by a line to junction 241, a fourth terminal 264,switch members 265, 266 and a solenoid coil 267 that is connected acrossjunctions 268, 269, junction 268 being connected by a line to junction241. When coil 267 is energized, switch member 265 moves to electricallyconnect terminals 261, 262 and switch member 266 moves to break theelectrical connection between terminals 263, 264. A solenoid coil 271 ofthe solenoid operated valve 270 is connected across junctions 268, 269,junction 269 being connected to junction 206. A solenoid coil 274 of thesolenoid operated valve, generally designated 273, is connected acrossrelay terminal 244 and junction 207.

A limit switch 276 has first, second and third terminals 277, 278, 279and a switch member 280 that is resiliently retained in a position toelectrically connect terminals 277, 278 but that is movable to break theaforementioned connection and electrically connect terminals 277, 279.Terminal 277 is connected by a line to junction 198, terminal 279 isconnected by a line to junction 281, and terminal 278 is connected by aline to the first terminal 285 of a solenoid relay 284. Relay 284includes a second terminal 286 and a fourth terminal 290 that areconnected by lines to junctions 255, 299, respectively, junction 255being connected to junction 299 which in turn is connected by a line tojunction 297'. Further relay 284 includes a third terminal 289 and afifth terminal 291 that are connected by lines to junction 300, a sixthterminal 292 connected by a line to junction 248 which in turn isconnected to junction 308, and a solenoid coil 296 connected acrossjunction 297, 298. When the relay 284 is energized, switch member 293electrically connects terminals 285, 286; switch member 294 electricallyconnects terminal 289, 290; and switch member 295 breaks the electricalconnection between terminals 291, 292. A solenoid coil 303 of a solenoidoperated valve, generally designated 302, is connected across junctions297 298. A solenoid operated valve, generally designated 306, has asolenoid coil 307 connected across junctions 208, 308 while a solenoidoperated valve 309 has a solenoid coil 310 connected across junctions209 and 308. A solenoid operated valve, generally designated 311 has asolenoid coil 312 connected across junctions 210, 300.

A relay 315 has a solenoid coil 317 connected across junctions 316 and281, junction 316 being connected to junctions 211, 298, a firstterminal 318, a second terminal 319, a third terminal 320, a fourthterminal 321, a switch member 322 and a switch member 323. Uponenergization of the coil 317, switch member 322 electrically connectsterminals 318, 319 while switch member 323 breaks the electricalconnection between terminals 320, 321. Terminal 319 is connected by aline to junctions 324 and 281 while a limit switch 325, resilientlyretained in a closed position, is connected across junction 199 andterminal 318. Coil 272 of the solenoid operated valve 270 is connectedacross junctions 324, 212. Terminal 321 is connected by a line toterminal 264 of relay 260 while terminal .320 is connected by a line tojunctions 326 and 327. A limit switch 330, resiliently retained in anopen position, is connected across junctions 200, 326 while a limitswitch 331 that is resiliently retained in an open position is connectedacross junctions 201, 327. The second solenoid coil 332 of valve 273 isconnected across junctions 327, 213.

A manually operated switch 333 which is resiliently retained in an openposition and a second solenoid coil 334 of valve 302 are connected inseries across junctions 202 and 335. Junction 335 is connected by a lineto junction 214.

A limit switch 340, resiliently retained in a closed position, isconnected across junctions 203, 341 while a limit switch 342,resiliently retained in an open position, is connected across junctions341, 343. The solenoid coil 344 of a relay 345 is connected acrossjunctions 343, 335, junction 343 being connected by a line to junction346. Relay 345 also includes a first terminal 347 connected by a line tojunction 341, a second terminal 348 connected by a line to junction 346and a switch member 349 that is movable by energization of coil 344to aposition to electrically connect terminals 347, 348. The solenoid coil351 of the solenoid operated valve 350 is connected across junctions346, 215.

The controls 353 of a conventional seam locator unit 572 (also see FIGS.9 and 10) include a plurality of relays that include relay terminals andnormally closed switch members 355 and relay terminals and a normallyopen switch member 356 that are connected in series across the junction358 of controls 353 and the junction 357 of the machine of thisinvention. Further the controls 353 include one winding of a transformer359 connected across junction 358 and a junction 360 of the machine ofthis invention. The transformer includes a secondary winding having alimit switch 361 that is resiliently retained in an open position; butwhich in a closed position actuates the automatic functioning of theseam locator unit for properly positioning the welding head 590 of theconventional welding machine 362 to carry out the welding steps.Junction 358 is connected by a line to junction 204 while junction 360is connected by a line to junction 216. Further, the welding machine hascontrols connected across junctions 218, 412 that upon energizationoperates the welder head to weld the members that are to be weldedtogether.

A relay 366 has a solenoid coil 367, first through sixth terminals,respectively, designated 368-373 and switch members 374-376. Uponenergization of coil 367, switch member 374 breaks the electricalconnection between terminals 368, 369; switch member 375 breaks theelectrical connection between terminals 370, 371; and switch member 376moves to electrically connect terminals 372, 373. The solenoid coil 367is connected across junction 360 and the fourth terminal 378 of a relay379. A limit switch 380 is connected across terminal 368 and junction357 while a limit switch 381 is connected across terminal 370 and ajunction 382 which in turn is connected by a line to junction 357. Limitswitches 380, 381 are resiliently retained in an open condition.Terminal 372 is connected by a line to junction 383 which in turn isconnected by a line to junction 204. Terminal 373 is connected by a lineto junction 384.

Relay 379 also includes first, second, third, fifth and sixth terminalsrespectively designated 386-390, a solenoid coil 391, and switch member392-394. When coil 391 is energized, switch member 392 breaks theelectrical'connection between terminals 386, 387; switch member 393breaks the electrical connection between terminals 388, 378; and switchmember 394 moves to make an electrical connection between terminals 389,390.

A relay 398 includes first through sixth terminals respectivelydesignated 399-404, switch members 405-407 and a solenoid coil 408connected across junction 217 and terminal 386. When the coil 408 isenergized, switch member 405 breaks the electrical connection betweenterminals 399, 400; switch member 406 breaks the electrical connectionbetween terminals 401, 402; and switch member 407 moves to establish anelectrical connection between terminals 403, 404. Terminal 399 isconnected by a line to terminal 371; coil 391 is connected acrossterminal 400 and junction 218; terminal 402 is connected by a line toterminal 388; and terminals 403, 389 are connected by a line to junction411 which is connected to junction .383. A limit switch 410 that isresiliently retained in an open position is connected across junction382 and terminal 401. Terminals 404, 373 are connected to junction 384,junction 384 being connected by lines to junction 412 and terminal 390.

Terminal 387 is connected by a line to terminal 369. The welder headcontrol 362 is connected across junctions 218 and 412.

Referring now to FIG. 13, the hydraulic control circuitry andcomponents, generally designated 17, will now be described. Thehydraulic controls 17 include a pump 426 driven by the motor 427, thepump pumping fluid under pressure from the sump 428 to the line Z whichhas junctions 429-433 thereon. Junction 429 is connected by a line to aninlet port 434 of the solenoid operated valve 302'. Valve 302 has asecond port 435 that is connectedby a line to port 443 of cylinder 46; athird port 436 connected by a line to the pressure reducing and flowcontrol valve 441, valve 441 in turn being connected to .port 442 ofcylinder 46; and a fourth port 437 that is connected to the sump. Valve302 includes a valve member 438 that is movable to a position that port434 is in fluid communication with port 435 and port 436 is in fluidcommunication with port 437 upon the energization of solenoid coil 334.The valve member is movable to a position that port 434 is fluidlyconnected to port 436 and port 435 to port 437 upon the energization ofcoil 303. Upon deenergization of the respective one of the coils 303,334, the valve member remains in the position it is in until the otherone of the coils is energized.

Mounted on the piston rod 45 is an operator 444 that with the rod in itsextended position, and upon applying fluid under pressure to port 442,moves to first operate limit switch 331 and then limit switch 342.

A check valve 446 is connected between junctions 445 and 430, junction445-being connected to the. inlet port 447 of the valve 350. Valve 350has a second port 449, a third port 450 and a fourth port 448 that isconnected to the sump. Valve 350 includes a valve member 457 that isresiliently retained in a position that port 447 is fluidly connected toport 449 and port 448 is fluidly connected to port 450. When coil 3S1isenergized, the valve member is moved to a position to fluidly connectport 447 to port 450, and port 448 to port 449, but upon de-energizationthe valve member is resiliently moved to break the last mentioned fluidconnections. Connected in a linebetween port 449 and junction 452 is aflow control 451 whilea corresponding fluid control is connected in linebetween port 450 and junction 453. Junction 452 is connected by a lineto ports 454 at the lower end of cylinders 70 while junction 453 isconnected to ports 455 at the upper ends of cylinders 70. An operator456 is secured to one of the piston rods 69 to upon the piston ofcylinder moving from it lowermost position to its uppermost position,first operate limit switch 257 and thence operate limit switch 236;while when the piston rod is moved to lower operator 456, it operateslimit switch 361 as will be described hereinafter.

Valve 273 includes a first port 460 connected to junction 445, a secondport 461 connected to junction 465, a blocked third port 462, and afourth port 463 that is connected to the sump. Valve 273 is of the sameconstruction as valve 302, valve 273 including a valve member 464 thatmoves to, or remains in, a position upon energization of coil 332 tofluidly connect port 460 to port 461 and port 463 to port 462; whileupon energization of coil 274, the valve member fluidly connects port460 to port 462, and port 461 to port 463.

Connected across junctions 465 and 467 is a needle valve 466, junction467 being connected to the cylinder 148 of the chuck assembly. Whenfluid under pressure is applied from junction 467 to the cylinder 148,the cylinder is moved relative its piston whereby the chuck hood ismoved relative the chuck body to a position that the chuck jaws areresiliently moved to a non-gripping position. However, when no fluidunder pressure is applied at junction 467, through spring mechanismprovided in the chuck assembly, the chuck hood moves relative the chuckbody to move the jaws to a rod clamping position and the cylinder ismoved relative the piston to a retracted position through springmechanism.

Junction 467 is connected to port 469 of cylinder 468 mounted on theframe adjacent assembly 15, a port 470 at the opposite end of thecylinder being connected to junction 471. The cylinder has a piston rod473 that upon application of fluid under pressure to port 470 moves inthe direction of the arrow 155, and moves in the opposite direction whenfluid under pressure is applied to port 469. An operator 474 is providedon piston rod 473 for moving switch member 280 of the limit switch 276to a position to connect terminals 277, 279 and retain the switch memberin that position when the piston rod 473 has moved the maximum amount inthe direction of arrow 155. Junction 471 is connected through a checkvalve 472 to the sump.

A needle valve 479 is connected between junction 465 and control port480 of valve 478. Valve 478 includes an inlet port 481 connected tojunction 431, a second port 482, a blocked third port 483, and a port484 that is connected to the sump. Further valve 478 includes a valvemember 485 that upon application of fluid under pressure at control port480 moves .to a position to fluidly connect port 481 to port 483, andport 482 to port 484; and that when no fluid under pressure is appliedat port 480, is moved by spring member 486 to fluidly connect port 481to port 482 and port 483 to port 484. The hydraulic motor 144 and aneedle valve 490 are connected in series between port 482 and junction471 with the needle valve being between the motor and the junction.

Valve 270 includes an inlet port 498 that is connected to junction 432,a second port 499, a thirdport 500, a fourth port 501 connected to the.sump, and a valve member 502. Valve member 502 is movable between threepositions, the neutral first position being diagrammatically illustratedin FIG. 13. In the first position, ports 499 and 500 are connected toport 501 while port 498 is blocked. In the second position, port 498 isfluidly connected to port 500 and port 499 is fluidly connected to port501; while in the third position port 498 is fluidly connected to port499 and port 500 is connected to port 501. When neither of the solenoidcoils 271 and 272 are energized, the springs 503, 504 resiliently retainvalve member 502in its first position; however, upon energization ofcoil 271, the valve member is moved against the action of the spring 503to the valve member second position. Upon energization of coil 272,valve member 502 is moved against the action of spring 504 to the valvemember third position.

Upon de-energization of coil 271, spring member 503 returns the valvemember 502 to its first position while upon de-energization of coil 272,spring 504 returns the valve member to its first position. It is beingmentioned that the control circuitry is such that both coils 271, 272are not energized at the same time.

A flow control 505 is connected between port 499 and-port 507 at one endof cylinder 120 while a second needle valve is connected between asecond port 508 of said cylinder and port 500. Upon the application offluid under pressure at port 507, the piston rod 119, if in a retractedposition, is moved in the direction of arrow 570 whereby the operator506 on the piston rod first moves switch 330 to a closed position,thence permits switch 330 opening, next operates limit switch 325 to anopen position and thereafter permits the limit switch moving to a closedposition.

Valve 31 1 which is of the same construction as valve 350, includes afirst port 512 that is connected to junction 433, a second port 513, athird port 514, a fourth port 515 that is connected to the sump, a valvemember 516 and a spring 517 for resiliently retaining the valve memberin a position that port 512 is connected to port 513 and port 514 isconnected to port 515. Upon energization of coil 312, the valve membermoves to a position to fluidly connect port 512 to port 514 and port 513to port 515. A flow control 518 is connected across port 513 and a port519 at the upper end of cylinder 102. The port 520 at the lower end ofcylinder 519 is connected to junction 535.

Port 514 of valve 311 is connected to port 525 of valve 309, a valve 309including a second port 526, a third port 527, a fourth port 528connected to the sump, a valve member 529 and a spring 530 thatresiliently retains the valve member in a position that port 526 isconnected to port 525 and port 527 is connected to port 528. Uponenergization of coil 310, port 525 is connected to port 527 and port 526is connected to port 528. A high pressure reducing valve 533 isconnected across port 526 and junction 535 while a low pressure reducingvalve 534 is connected across port 527 and junction 535.

The first port 540 of valve 306 is connected to junction 433, valve 306including a blocked second port 541, a third port 542, a fourth port 543connected to the sump, and a spring member 545 resiliently retainingvalve member 544 in a position that port 540 is fluidly connected toport 541 and port 542 is fluidly connected to port 543. Uponenergization of coil 307, valve member 544 moves to a position toconnect port 540 to port 542 and port 543 to port 541. Hydraulic motor96 and a needle valve 547 are connected in series across port 542 andthe sump, the hydraulic motor being in intermediate the needle valve andport 542.

Referring to FIGS. 3 and 13, the mechanism for moving limit switches380, 381 and 410 to their closed positions includes an upright 554mounted on base 36, upright 554 rotatably mounting a shaft 553 parallelto shaft 39. Intermeshing gears 551, 552 are keyed on shafts 39, 53,respectively, while a drum 555 is mounted on shaft 553 to rotatetherewith. The drum has axially spaced, circumferential strips 556, 557and 558 for respectively operating limit switches 380, 381 and 410 toclosed positions. The circumferential length of the camjsurface portionsof strips 556, 557 and 558 in cooperation with the gear ratios betweengears 551 and 552 is such that the respective one of the limit switches380, 382 and 410 will be retained in the closed position for slightlymore than two revolutions of the shaft 39. Further the cam surfaceportion of strips 556, 557 and 558 are angularly spaced approximatelyrelative to one another on the circumferential surface of the drum.

For purposes of facilitating the description of this invention, theapparatus of this invention is usable for welding a pin 561 having athreaded end portion to one end of a rod portion and a box 562 having aninternal threaded portion to the opposite end of a second rod portion.The pin and box' are separately formed and then threaded together, thepin and box in a threaded together condition preferably having opposedtapered end surfaces remote from their threaded ends that extendradially inwardly and axially away from the threaded portion, and thenceaxially inwardly. Each end of the rod portions preferably are providedwith tapered annular surfaces 566, 567 that are tapered radiallyinwardly and axially away from the opposite end of the respective rodportions. The structure of a completed drill stem rod is more fullydescribed in the copending application entitled Composite Rods mentionedabove.

Upon depressing switch 176 to a closed position, relay moves its switchmembers 186, 189 to closed positions whereby a hold in circuit isprovided through switch member 186 to retain coil 179 energized eventhough switch 176 resiliently returns to its open position. Thisprovides for the hydraulic pump being energized, whereupon pushingswitch 222, relay 229 is energized to energize motor 427 and provide ahold in circuit to maintain the motor energized. As a result, fluidunder pressure is applied to line Z and through valve 350 to the lowerends of the cylinders 70 for pivoting the rod hold down assembly fromthe solid line position of FIG. 4 to the dotted line position.

Now a first drill stem rod portion 563 is placed on the cradle assemblywith one end portion adjacent the live center member 40 with said livecenter in the solid line position of FIG. 3. At this time, the other endof rod portion 563 as viewed in FIGS. 1 and 2 is to the left of thelinear travel assembly 14. A pin and'box combination 561, 562 that arethreaded together are placed on the roller subassembly T with one end ofthe combination facing rod portion 563 while a second rod portion 564 isplaced on the cradle assembly to have its ends as viewed in FIG. 2 tothe right of the threaded pin and box combination of 561, 562. In thisconnection, it is assumed that the rod positioner assembly is in theposition illustrated in FIG. 1, that the chuck travel assembly is to theopposite end of its path of longitudinal reciprocation from the positionillustrated in FIG. 1, and that the piston rod of the linear travelassembly is in its retracted position whereby a rod portion supported onthe cradle assembly may be freely axially moved between rollers 106 and98.

Further, it will be assumed that at the time motor 427 was energized,that valve 273 is in the position indicated in FIG. 13, and as a result,the application of fluid under pressure to line Z results in fluid underpressure being applied to the control port 480 whereby valve member 485moves to the position of FIG. 13 to block the application of fluid underpressure to the hydraulic motor 144; and also fluid under pressure isapplied to the chuck cylinder 148 whereby it results in the chuck hoodbeing moved to a position that the chuck jaws are in a non-clampingposition. Thence switch member 191 is moved to its closed position andremains in its closed condition until moved to its open position:

With switch 191 in its closed position, switch 333 is closedsufficiently long to energize coil 334 of valve 302, switch 333 thenreturning to an open position. This results in valve member 438 movingto a position that fluid under pressure is applied to port 442 ofcylinder 46. The resulting movement of the piston rod 45 in thedirection of arrow 570 moves the rod positioner live center member 40 inthe same direction and thereby rod portion 563 toward the chuckassembly. Member 40 has a minor base of a diameter smaller than travelassemblies are moved for retaining rod portions 553, 564 and the pin andbox combination in compression in axial alignment with one another justprior to the rod hold down rollers 78 holding the rod portions againstthe cradle assembly. Since motor 85 is beingcontinuously driven, rollers78-now rotate rod members 561-564 and therethrough live center members40, 140.

Just as the rollers 78 move to positions to clampingly hold the rodportions against the cradle assembly rollers, operator 456 moves switchmember 361 to a closed position, and retains it in a closed positionuntil i the rollers are elevated, this actuating circuitry in the ningmembers 561-564. Operator 444 in'moving in the direction of arrow 570moves limit switch 331 to a closed positionand retains it in a closedposition for a sufficient period of time that relay coil 267 isenergized and moves its switch member 265 to form a hold in circuitprior to switch member 266 opening and to energize coil 332 of valve 273to move valve member 464 to form a fluid connection between ports 460,461 (Provided the valve member is not already in this position), wherebythe chuck jaws are in a non-clamping position as previously indicated.After this occurs, operator 444 is moved away from switch member 331 topermit it to open.

Further, at the same time coil of relay 260 is energized, coil 271 ofvalve 270 is also energized. As a result valve member 502 moves to applyfluid under pressure to port 508 whereby piston rod 119 moves the chucktravel assembly in the direction of the arrow 155. This movement of thechuck travel assembly moves the chuck relative rod portion 564 so thatthe rod portion extends thereinto, and upon the live center member 140abutting against rod portion 564, move said rod portion in the directionof the arrow 155.. In

this connectionthe minor base of member 140 is of a smaller diameterthan the inside diameter of rod por-- energized and moves its switchmember 349 to retain said relay in an energized condition after switchmember 342 moves to an open condition. At the same time the relay 345 isenergized, valve 350 is energized to move valve member. 457 to aposition that fluid under pressure is applied through the upper ports455 of cylinders 70 to pivot the rod hold down assembly from the dottedline position of FIG. 4 toward its solid line position. The rate ofmovement of the rod hold down frame about pivots 63 in the direction ofthe arrow 571 is controlled such that switch 342 moves to an openposition and the rod positioner and chuck welder machine that per sedoes not form a part of this invention, and accordingly, the operationof the welder machine will not be described in enough detail tounderstand the functioning thereof to carry out the welding steps. Uponclosing of switch 361, the internal circuitry (not shown) of thecontrols of the seam locator unit 572 moves its carriage 591 along track592 and its probe 572a relative the carriage (the probe being mounted onthe carriage) to sense the presence of the groove of the rod portion563, pin 561. The welder head 590 is mounted on the carriage to movetherewith. Upon the probe being adjacent the last mentioned groove, themovement of the carriage is stopped, the electrode 572b of the welderhead now being positioned for heating the portions of the rod portion563 and pin 561 at the groove, and the weld rod feed 5320 is properlypositioned to be fed to commence the welding operation.

As members 561-564 are being rotated (it being noted that live centermembers 40 and 140 are free to rotate while retaining members 561-564 inaxial compression), drum 555 is rotated relative switches 380, 381, 410.Once the welder head 590 is correctly positioned for welding the pin androd portion 563 together at the groove, all the relays 355, 356 areclosed, and upon closure of one of the limit switches 380, 381, 410, thewelding step begins. In this connection, it is to be noted. that thelimit switches have been provided in order that the rod portions 563,564 have to be rotatedv a maximum of about after the welder head 572 isproperly positioned to commence the welding operation. Assuming thatlimit switch 380 is the first one closed after the completion of all therelays 355, 356, the closing of the switch 380 results in coil 408 beingenergized. The energization of coil 408 opens switch members 405, 406 toprevent relays 366, 379 being energized and moves switch member 407 toenergize welder circuitry of the welder machine 362. The energization ofwelder 362 results in power being applied at electrode 572b of thewelder head and the weld rod feed 5720 for welding the rod portion 563and pin 361 together at groove 566. It is to be mentioned thatpreferably an atmosphere of argon or helium or mixture thereof surroundsthe location of the welding of pin 561 to rod portion 563. The weldingcontinues for 2 or 3 beyond two complete revolutions of rod portions 563whereupon the drum 555 has rotated so that switch member 380 opens tode-energize the controls of welder machine 362, the de-energization' ofthe welder machine controls completing the actuation of controls (notshown) of the seam locator unit to move the welder head in the directionof the arrow 570 and extend probe 572a to sense the location of thegroove formed in part by surface 567. Once the welder head is properlypositioned for welding the box and rod portion 564 together at groove567, the longitudinal movement of the carriage and the welder head isstopped, the probe 572a withdrawn and relay members 355, 356 are allclosed so that upon the closing of one of the limit switches 380, 381and 410, the welder machine 362 is again energized for welding the boxand rod portion 564 together in the manner described with reference towelding the rod portion 563 and 561 together. At the end of the justover two complete revolutions of rod portion 563, the one of relays 366,398 and 379 that completed the circuit for actuating control 362 isdeenergized through the opening of the respective limit switch to stopthe welding operation; and the stopping of the welding operationresulting in theseam locator carriage 591 moving to open limit switch340 for a short time prior to the carriage automatically being moved inthe direction opposite arrow 570 to its datum position. In thisconnection, it is to be noted that the completion of the welding step,one of the relays 355, 356 opens as a result of the deenergization ofcontrol 362.

At the time the welding at each of the grooves is complete, throughappropriate circuitry, gas is applied at nozzles 575 and ignited bypilots 574 to carry out a post heat operation of the welds.

Limit switch 340 is retained in an open condition for Q a long enoughperiod to de-energize relay 345 (switch member 349 opening to break thehold in circuit). This regults in coil 351 being de-energized and as aresult valve member 457 is resiliently moved to a position to applyfluid under pressure to the lower ends of cylinders 70. This pivots therod hold down subframe in the direction of the opposite arrow 571, theinitial movement of operator 456 permitting limit switch 361 moving toan open condition. Further the initial movement of the rod hold downassembly from its rod hold down position results in the rollers 78moving out of engagement with the drill stem rod portions and therebythe rotation of the drill stem rod portions is discontinued. As operator456 moves further upwardly, it engages limit switch 257 to move it to aclosed position and retain it in a closed position for a sufficient timethat coil 274 is energized to move valve member 464 to fluidly connectport 461 to port 463. This results in operation of the chuck for movingthe chuck jaws 152 into a clamping position with rod portion 564, andalso results in discontinuance of application of fluid under pressure atcontrol port 480.

The discontinuance of fluid under pressure at port 480 results in valvemember 485 moving to fluidly connect port 481 to port 482 and therebyapply fluid under pressure to hydraulic motor 144, and therethrough toport 470 of cylinder 469. This results in motor 144, through gears 143,142, rotating the chuck body 151, the chuck hood 150 and the chuck jaws152 to rotate rod portion 564 in an unthreading direction relative torod portion 563 (i.e., to unthread the pin and box).

Prior to the start of the rotation of chuck members 150-152, the rodhold down assembly operator 456 has moved to aposition to move switchmember 254 of switch236 to break the electrical connection betweenterminal 251, 252 and electrically connect terminal 251 to terminal 253.This movement of switch member 254 de-energizes relay 260 to break itshold in circuit and de-energize coil 271 of relay 270. Thedeenergization of coil 271 results in the spring 503 moving valve member502 to its first position whereby ports 499 and 500 are fluidlyconnected to the sump. Thus the chuck assembly 133 is free to move ineither longitudinal direction along the guide rods, in a floatcondition.

The movement of the switch member 254 to electrically connect terminals251, 253 results in relay 284 being energized, switch member 293 closingto form a hold in circuit, switch member 295 opening to preventenergization of valves 306, 309; and switch member 294 closing toenergize coil 312 of valve 311. Thence operator 456 moves out ofengagement with switch 236 whereupon the connection between terminals251, 253

is broken and the connection between terminals 251, 252 is closed. Atthe same time relay 284 is energized, solenoid coil 303 of valve 302 isenergized. The energization of coil 303 results in valve member 438moving to a position to fluidly connect port 434 to port 435 and port436 to port 437. As a result the piston rod 45 of the rod positionerassembly moves in the direction of the arrow to move the rod positionerassembly to its datum position.

The aforementioned energization relay 284 energizes valve 311 to movevalve member 516 to a position that port 512 is connected to port 514and port 513 to port 515 to provide a fluid under pressure throughpressure reducing valve 533 to port 520 of cylinder .102. This movesroller 106 upwardly with sufficiently high pressure to clamp rod portion563 between rollers 98,106 to prevent rotation and axial movement of rodportion 563.

With rod portion 563 being clamped by rollers 98, 106 to preventrotation thereof, and rod portion 564 being clamped by the chuck jaw torotate therewith, the rotation of the chuck results in the box 562 beingangularly and axially moved in an unthreading direction to disconnectthe box from the pin. Due to rod portion 563 being held in its fixedaxial position,

the unthreading movement of the box results in the chuck assembly beingmoved in the direction of arrow 570 along the guide rods 120.

The number of rotations of the motor shaft of motor 144 is controlleddue to fluid under pressure passing through the motor passing throughport 470 to move. the piston rod 473 from its retracted position towardsits fully extended position. That is, after sufficient fluid has passedthrough the motor to turn it the proper number of revolutions, thepiston rod 473 has moved its operator into engagement with limit switch276. This moves switch member 280 to break the electrical connectionbetween terminals 277, 278 and provide an electrical connection betweenterminals 277, 279. Electrically connecting terminals 277, 279 energizesrelay 315 and coil 272 of valve 270 while the breaking of electricalconnection between terminals 277, 278 results in relay 284 beingde-energized and coil 303 of valve 302 being de-energized. Theenergization of coil' and the rod portion 564 and box 562 in the sameaxial direction.

The energization of relay 315 results in switch member 323 moving toblock energization of coil 332 until either limit switch 330 or 331 isclosed (as long as relay 315 is energized) and switch member 322 movingto a closed position to, in conjunction with limit switch 325, provide ahold in circuit for maintaining relay 315 energized. The de-energizationof relay 284 results in switch members 293, 294 moving to open positionswhereby valve 311 is de-energized and valve member 516 resiliently movesto apply fluid under pressure to the upper port 519 of cylinder 102. Asa result, roller 106 is moved downwardly out of engagement with rodportion 563. Further, the tie-energization of relay 284.

results in coil 303 of valve 302 being de-energized.

After chuck assembly is moved a short distance in the direction of arrow570 from its float position, the operator S06 closes limit switch 330 toenergize coil 332 of valve 273 to move its valve member to a position sothat fluid under pressure is applied to the chuck cylinder 148andoperates the chuck to a chuck jaw release position. Further movementof the chuck assembly results in the chuck live center member 140 beingmoved away from the adjacent end of rod portion 564. At the same timefluid under pressure is applied to the chuck cylinder 148, fluid underpressure is applied to control port 480 to move valve member 485 toconnect port 482 to port 484; and fluid'under pressure is applied'atport 469 to move piston rod 473 in the direction of the arrow 570. Themovement of piston rod 473 in the direction of the arrow 570 movesoperator 474 away from limit switch 276. As a result, switch member 280of the limit switch breaks the electrical connection between terminals277, 279 and establishes an electrical connection between terminals 277,278, it being noted that relay 284 is de-energized at this time andrelay 315 remains energized through its hold in circuit.

As the piston rod 119 of the chuck travel assembly continues to move inthe direction of the arrow 570, operator 506 is moved into engagementwith limit switch 325 to open said limit switch, limit switch'325opening after the switch member-280 has returned to a position toelectrically connect terminals 277, 278. As

a result, the hold in circuit for re'lay 315 is broken to de-energizethe relay and coil 272 of valve 270 whereupon ports 499, 500 areconnected to port 501. Prior to the discontinuation of the applicationof fluid under pressure at port 507, the operator 506 is movedsufficiently to permit limit switch 325 closing. At this time,

' the chuck travel assembly piston rod is in its fully extended positionwhereby the right hand end of rod portion 564 as viewed in FIGS. 1 and 2is to the left of the chuck.

Now the rod portion 564 with the box 562 welded thereto is'removed fromthe cradle assembly, and thereafter switch 239 is manually operated tomove switch member 242 to electrically connect terminals 238, 240 andswitch member 247 to electrically connect terminals 245,- 246. Thiscompletes a circuit for energizing relay 260 and coil 271 of valve 270.The energizationof relay 260 provides the hold in circuit bypassingswitch member 242 while the energization of coil 271 moves valve member502 that the chuck is moved in the direction of arrow 155.

The moving of switch member 247 to connect terminals 246, 245 provides acircuit to energize coils 307, 310, 312 of valves 306, 309 and 311,respectively. With both valves 309, 311 energized, the valve members aremoved to apply fluid under pressure through ports 525, 527 through thelow pressure reducing valve 534and thence to the lower port 520 ofcylinder 102. As a result, roller 104 is moved upwardly with sufficientpressure to hold rod portion 563 in driven abutting relationship withroller 98 while not blocking axial movement of the rod portion 563.

. The energization of valve 306 applies fluid under pressure tohydraulic motor 96 to drive a shaft and thereby roller 98 in thedirection to act in cooperation with roller 106 to move rod portion 563in the direction of the arrow 570 until the left hand end portion ofsaid port as viewed in FIG. 2 moves to the left of the vertical planebetween the axis of rollers 106, 98. At this time the switch 239 isoperated to break the electrical connection between terminals 245, 246whereupon valves 309, 306 and 311 are de-energized and thence rodportion 563 further manually moved in the direction of the arrow 570 tothe right of roller assembly T as viewed in FIG. 2, and thereafter, asecond pin and box combination placed on roller assembly T. Thence asecond rod portion 563 is positioned on the cradle assembly to belongitudinally intermediate the live center member of the rod positionerand the linear travel assembly 14.

Now the second rod portion 563, the second pin and box combination 561,562 and the first rod portion 563 which now has a pin welded on its endadjacent the chuck are generally longitudinally aligned on the cradleassembly. Thence button 330 is moved to a closed position for asufficient time to energize coil 334 of valve 302; this applying fluidunder pressure to the end of the rod position cylinder 46 whereby thepiston rod 45 is moved in the direction of the arrow 570. The cycle ofoperation is the same as previously described other than that relay 260has already been energized through the previously described operationsof switch 239 and remains in an energized condition through its hold incircuit even though switch member 242' has broken the electricalconnection between terminals 238, 240. Thus, at this time, the closingof limit switch 331 energizes coil 332 of valve 273 which was notpreviously energized since relay switch member 266 had opened prior tothe energization of said coil. Thereafter the cycle of operation is thesame, it being noted that upon the completion of the cycle to the pointthat the second rod portion 563 is removed from the cradle assembly, thesecond rod portion has a box welded on one end and a pin welded on theopposite end thereof.

To be mentioned is that each of the limit switches 236, 257, 276, 325,330, 331, 361, 340 and 342 are of the type that they are moved from thepositions they are resiliently retained in only when the operators aremoved in the above described indicated direction and not in the oppositedirection.

By using the apparatus of this invention, the pins and boxes may bereadily made atone location or country and thence shipped to anotherlocation or country to be welded to rod portions to form drill rods. Inthis connection, it is to be noted that in making the pin and box, moreprecise manufacturing operations have to be carried out than in makingthe rod portions, and that it is preferable to use a higher qualitysteel for the pin and box than the rod portions and the higher steel maynot be made at the location or country where the drill rod is to bemade. Thus, the lower quality steel rod blanks, which form the majorpart of the drill rod, and is satisfactory for the rod portion, may beused without having to ship the rod portions long distances.

During the welding steps, each of pin 561 and rod portion 563', and box562 and rod portion 564 are joined together by an externalcircumferential weld bead 580 filling the respective groove and aninternal annular weld bead 481 such as indicated in FIG. 11 for the boxand rod portion 564, the rod portions being fused throughout to the pinand box, respectively, at the abutting tapered surfaces intermediatebeads 480, 481.

A suitable seam locator unit 572 for use in this invention is sold underthe trade designation Special Seam Locator, Model CMS-9A, by CecilEquipment Co., Cleveland, Ohio. A suitable welding machine 362 for usein this invention is sold under the trade designation Contour Welder,Model HWM3, Linde Co., a division of Union Carbide Corp.

What is claimed is: v

1. Rod welding apparatus'for welding a first, a second and a third rodmember together, each rod member having a central axis, comprising alongitudinally elongated frame having a first end portion, a

' second end portion and an intermediate portion, first means mounted onthe frame intermediate portion for supporting the rod members in axialalignment with the second rod member intermediate the first and thirdrod members, second means mounted on the frame second portion to abutagainst the third rod member to limit axial movement of the rod memberson the first means in a longitudinal direction from the first endportion toward the second end portion, third means mounted on the framefor cooperating with the second means to releasably retain the three rodmembers in axial alignment on the first means in axial compression androtate the rod members about their axes while being retained in axialcompression, and fourth means for welding the adjacent ends of the firstand second rod members together and the, adjacent ends of the second andthird rodmembers together while the rod members are being rotated by thethird means, the first means comprising a plurality of longitudinallyspaced roller assemblies mounted on the frame intermediate portion, eachroller assembly having a pair of rollers, and means to rotate the pairof rollers with the rollers having transversely spaced, longitudinalaxes of rotation, and that the third means includes a longitudinallyelongated shaft, a plurality of longitudinally spaced rollers'mounted onsaid shaft, and fifth means mounted on the frame intermediate portionfor mounting the shaft and moving the shaft between a first positionthat the third means rollers are substantially spaced from the rollerassemblies and a second position that the third means rollers abutagainst two of the aligned rod members to rotatably retain the rodmembers in axial alignment on the roller assemblies.

2. Rod welding apparatus for welding a first, a second and a third rodmember together, each rod member having a central axis, comprising alongitudinally elongated frame having a first end portion, a second endportion and an intermediate portion, first means mounted on the frameintermediate portion for supporting the rod members in axial alignmentwith the second rod member intermediate the first and third rod members,second means mounted on the frame second portion to abut against thethird rod member to limit axial movement of the rod members on the firstmeans in a longitudinal direction from the first end portion toward thesecond end portion, third means mounted on the frame for cooperatingwith the second means to releasably retain the three rod members inaxial alignment on the first means in axial compression and rotate therod members about their axes while being retained in axial compression,and fourth means for welding the adjacent ends of the first and secondrod members together and the adjacent ends of the second and third rodmembers together while the rod members are being rotated by the thirdmeans, each of the second and third means including a live center memberabuttable against the remote ends of the first and third rod members,means for rotatably mounting the respective live center members andmeans mounted on the frame for longitudinally reciprocating at least oneof the live center member mounting means a limited distance.

3. The apparatus of claim 1 further characterized in that each of thesecond and third means includes a live center member abuttable againstthe remote ends of the first and third rod members, means for rotatablymounting the respective live center members and means mounted on theframe for longitudinally reciprocating the respective live center membermounting means a limited distance.

4. The apparatus of claim 3 further characterized in that the second rodmember comprises a threaded together pin and box combination, that theabutting ends of the first and second rod members and the second andthird rod members respectively have matching tapered surface portionsabutting against one another when the rod members are being retained inaxial compression, that the second means includes a hydraulic chuckassembly having a longitudinal opening extending therethrough to open tosecond means live center member, chuck jaws movable between a rod memberclamping position and a rod release position and a chuck body formounting the jaws for movement between their positions, that the secondmeans live center member mounting means includes rotatable sixth meansfor mounting the live center member for Y rotation relative thereto andthe chuck body to rotate therewith, and seventh means for drivi glyrotating the sixth means. i

5. The apparatus of claim 4 in that there is provided operable eighthmeans for clampingly holding the first rod member against rotation andcontrol means to operate the eighth means to clampingly hold the firstrod portion, the chuck jaws to their rod clamping position to clampinglyhold the third rod portion and thence the seventh means to rotate thesixth means in a direction to unthread the pin from the box after theadjacent ends of the second rod member have been welded to the firstand-third rod members respectively.

6. Rod welding apparatus for welding a first, a second and a third rodmember together, each rod member having a central axis, comprising alongitudinally elongated frame having a first end portion, a second endportion and an intermediate portion, first means mounted on the frameintermediate portion operable between a first condition for supportingthe rod members in axial alignment with the second rod memberintermediate the first and third rod members and a second conditionrotating the rod members and holding at least one of the rod membersagainst transverse and lateral movement, second and third meansrespectively mounted on the first end portion and the second end portionfor cooperatively holding the rod portions on the first means in thefirst condition in axial compression and retaining the rod members inaxial compression while permitting the rod members to rotate when thefirst means is in its second condition, the second means being abuttableagainst the first rod member end that is remote from the second rodmember and the third means being abuttable against the third rod memberend that is remote from the second rod member, fourth means mounted onthe frame first end portion for mounting the second means for limitedlongitudinal movement toward and away from the third means, fifth meansfor mounting the third means on the frame second end portion and weldermeans for welding the adjacent ends of the first and second rod membersand the adjacent ends of the second and third rod members.

7. The apparatus of claim 6 further characterized in that each of thesecond and third means includes a live center member abuttable againstthe end of the first and third rod members respectively that is adjacentthereto and means for mounting the respective live center member forrotation about coextensive longitudinal axes.

8. The apparatus of claim 7 further characterized in that the firstmeans includes a cradle assembly for supporting the rod members inlongitudinal alignment for rotation about a common longitudinal axis.and a rod hold down assembly mounted on the frame for movement between arod hold down position and a datum position more remotely spaced fromthe cradle assembly than the rod hold down position.

gaged thereby, a hold down assembly-for holding the rod portions infixed transverse positions on the cradle assembly while permittingrotation of the rod portions about said longitudinal axis, said hold'down'assembly being mounted on the intermediate portion for movementbetween a datum first position and a rod hold 9. Rod welding apparatusfor welding the first end of intermediate portion and a secondendportion, a cradle assembly mounted on the frame for supporting therod portions in longitudinally extending, axially aligned relationshipwith the first rod portion extending adjacent the first end portion andthe second rod portion extending adjacent the second end portion, achuck assembly mounted on the second end portion for engaging theadjacent end portion of the second rod portion to retain the second rodportion against movement in a longitudinal direction from the first endportion toward the second end portion for a first interval of time whenpermitting rotation of the second rod portion about a longitudinal axisof the rod portions supported on the cradle assembly, a rod positionerassembly mounted on the first end portion for longitudinal movementbetween a datum first position and a second position abutting againstthe second end of the first rod portion to retain the first end of thefirst rod portion against the first end of the second rod portion thatis remote from the chuck assembly when the second rod portion is endownposition, and including first means for rotating the rod portions aboutthe longitudinal axis when the rod hold down assembly is in its rod holddown position, and welding means for welding the rod portions to joinsaid rod portions first ends together as the rod portions are beingrotated by the first means and the rod portions extend o'n the cradleassembly between the rod positioner assembly in its second position andthe chuck assembly and the second rod portion abuts against the chuckassembly during said first interval of time.

10. The apparatus of claim 9 further characterized in that the chuckassembly has a live center member to abut against the second rod portionsecond end while the rod portions are being held against the cradleassembly by the rod hold down assembly in its rod hold down position,and second means for mounting the live center member on the frame forrotation about said longitudinal axis.

l 1. The apparatus of claim 10 wherein one of the rod portions, includesseparately threaded pin and box members, further characterized in thatthere is provided third means on the frame operable between a firstposition for clampingly engaging the first rod portion that abutsagainst the rod positioner assembly to block rotation of the first rodportion and a second position permitting rotation of the first rodportion, that the second means includes fourth means for mounting thelive center member for rotation about said longitudinal axis, a housing,fifth means rotatably mounting the fourth means in a longitudinallyfixed position in the housing, said fifth means being rotatably mountedby the housing, sixth means mounting the housing for longitudinalmovement on the frame, said fifth means including seventh means forreleasably clampingly holding the adjacent end of the second rodportion, and eighth means for drivingly rotating the fifth means,including the seventh means, about the longitudinal axis, and that thereis provided control means for actuating the seventh means to clampinglyhold the second rod portion, and the eighth means to rotate the fifthmeans fora selected interval when the seventh means clampingly holds thesecond rod portion and operate the third means to its first positionbefore the eighth means rotates the fifth means and after the selectedinterval operate the third means to its second position. v

12. The apparatus of claim 11 further characterized in that there isprovided operable ninth means. on the frame for longitudinally movingthe sixth means between a first position remote from the first endportion and a second position more closely adjacent the first endportion and that the control means includes means for actuating theninth means to move the sixth means between its positions and to permitfloating longitudinal movement of the sixth means when the second rodportion.

1. Rod welding apparatus for welding a first, a second and a third rodmember together, each rod member having a central axis, comprising alongitudinally elongated frame having a first end portion, a second endportion and an intermediate portion, first means mounted on the frameintermediate portion for supporting the rod members in axial alignmentwith the second rod member intermediate the first and third rod members,second means mounted on the frame second portion to abut against thethird rod member to limit axial movement of the rod members on the firstmeans in a longitudinal direction from the first end portion toward thesecond end portion, third means mounted on the frame for cooperatingwith the second means to releasably retain the three rod members inaxial alignment on the first means in axial compression and rotate therod members about their axes while being retained in axial compression,and fourth means for welding the adjacent ends of the first and secondrod members together and the adjacent ends of the second and third rodmembers together while the rod members are being rotated by the thirdmeans, the first means comprising a plurality of longitudinally spacedroller assemblies mounted on the frame intermediate portion, each rollerassembly having a pair of rollers, and means to rotate the pair ofrollers with the rollers having transversely spaced, longitudinal axesof rotation, and that the third means includes a longitudinallyelongated shaft, a plurality of longitudinally spaced rollers mounted onsaid shaft, and fifth means mounted on the frame intermediate portionfor mounting the shaft and moving the shaft between a first positionthat the third means rollers are sUbstantially spaced from the rollerassemblies and a second position that the third means rollers abutagainst two of the aligned rod members to rotatably retain the rodmembers in axial alignment on the roller assemblies.
 2. Rod weldingapparatus for welding a first, a second and a third rod member together,each rod member having a central axis, comprising a longitudinallyelongated frame having a first end portion, a second end portion and anintermediate portion, first means mounted on the frame intermediateportion for supporting the rod members in axial alignment with thesecond rod member intermediate the first and third rod members, secondmeans mounted on the frame second portion to abut against the third rodmember to limit axial movement of the rod members on the first means ina longitudinal direction from the first end portion toward the secondend portion, third means mounted on the frame for cooperating with thesecond means to releasably retain the three rod members in axialalignment on the first means in axial compression and rotate the rodmembers about their axes while being retained in axial compression, andfourth means for welding the adjacent ends of the first and second rodmembers together and the adjacent ends of the second and third rodmembers together while the rod members are being rotated by the thirdmeans, each of the second and third means including a live center memberabuttable against the remote ends of the first and third rod members,means for rotatably mounting the respective live center members andmeans mounted on the frame for longitudinally reciprocating at least oneof the live center member mounting means a limited distance.
 3. Theapparatus of claim 1 further characterized in that each of the secondand third means includes a live center member abuttable against theremote ends of the first and third rod members, means for rotatablymounting the respective live center members and means mounted on theframe for longitudinally reciprocating the respective live center membermounting means a limited distance.
 4. The apparatus of claim 3 furthercharacterized in that the second rod member comprises a threadedtogether pin and box combination, that the abutting ends of the firstand second rod members and the second and third rod members respectivelyhave matching tapered surface portions abutting against one another whenthe rod members are being retained in axial compression, that the secondmeans includes a hydraulic chuck assembly having a longitudinal openingextending therethrough to open to second means live center member, chuckjaws movable between a rod member clamping position and a rod releaseposition and a chuck body for mounting the jaws for movement betweentheir positions, that the second means live center member mounting meansincludes rotatable sixth means for mounting the live center member forrotation relative thereto and the chuck body to rotate therewith, andseventh means for drivingly rotating the sixth means.
 5. The apparatusof claim 4 in that there is provided operable eighth means forclampingly holding the first rod member against rotation and controlmeans to operate the eighth means to clampingly hold the first rodportion, the chuck jaws to their rod clamping position to clampinglyhold the third rod portion and thence the seventh means to rotate thesixth means in a direction to unthread the pin from the box after theadjacent ends of the second rod member have been welded to the first andthird rod members respectively.
 6. Rod welding apparatus for welding afirst, a second and a third rod member together, each rod member havinga central axis, comprising a longitudinally elongated frame having afirst end portion, a second end portion and an intermediate portion,first means mounted on the frame intermediate portion operable between afirst condition for supporting the rod members in axial alignment withthe second rod member intermediate the first and third rod members and asecond conditIon rotating the rod members and holding at least one ofthe rod members against transverse and lateral movement, second andthird means respectively mounted on the first end portion and the secondend portion for cooperatively holding the rod portions on the firstmeans in the first condition in axial compression and retaining the rodmembers in axial compression while permitting the rod members to rotatewhen the first means is in its second condition, the second means beingabuttable against the first rod member end that is remote from thesecond rod member and the third means being abuttable against the thirdrod member end that is remote from the second rod member, fourth meansmounted on the frame first end portion for mounting the second means forlimited longitudinal movement toward and away from the third means,fifth means for mounting the third means on the frame second end portionand welder means for welding the adjacent ends of the first and secondrod members and the adjacent ends of the second and third rod members.7. The apparatus of claim 6 further characterized in that each of thesecond and third means includes a live center member abuttable againstthe end of the first and third rod members respectively that is adjacentthereto and means for mounting the respective live center member forrotation about coextensive longitudinal axes.
 8. The apparatus of claim7 further characterized in that the first means includes a cradleassembly for supporting the rod members in longitudinal alignment forrotation about a common longitudinal axis and a rod hold down assemblymounted on the frame for movement between a rod hold down position and adatum position more remotely spaced from the cradle assembly than therod hold down position.
 9. Rod welding apparatus for welding the firstend of a first axially elongated rod portion to a first end of a secondaxially elongated rod portion, each of said rod portions having a secondend, comprising a longitudinally elongated frame having a first endportion, an intermediate portion and a second end portion, a cradleassembly mounted on the frame for supporting the rod portions inlongitudinally extending, axially aligned relationship with the firstrod portion extending adjacent the first end portion and the second rodportion extending adjacent the second end portion, a chuck assemblymounted on the second end portion for engaging the adjacent end portionof the second rod portion to retain the second rod portion againstmovement in a longitudinal direction from the first end portion towardthe second end portion for a first interval of time when permittingrotation of the second rod portion about a longitudinal axis of the rodportions supported on the cradle assembly, a rod positioner assemblymounted on the first end portion for longitudinal movement between adatum first position and a second position abutting against the secondend of the first rod portion to retain the first end of the first rodportion against the first end of the second rod portion that is remotefrom the chuck assembly when the second rod portion is engaged thereby,a hold down assembly for holding the rod portions in fixed transversepositions on the cradle assembly while permitting rotation of the rodportions about said longitudinal axis, said hold down assembly beingmounted on the intermediate portion for movement between a datum firstposition and a rod hold down position, and including first means forrotating the rod portions about the longitudinal axis when the rod holddown assembly is in its rod hold down position, and welding means forwelding the rod portions to join said rod portions first ends togetheras the rod portions are being rotated by the first means and the rodportions extend on the cradle assembly between the rod positionerassembly in its second position and the chuck assembly and the secondrod portion abuts against the chuck assembly during said first intervalof time.
 10. The apparatus of claim 9 further Characterized in that thechuck assembly has a live center member to abut against the second rodportion second end while the rod portions are being held against thecradle assembly by the rod hold down assembly in its rod hold downposition, and second means for mounting the live center member on theframe for rotation about said longitudinal axis.
 11. The apparatus ofclaim 10 wherein one of the rod portions includes separately threadedpin and box members, further characterized in that there is providedthird means on the frame operable between a first position forclampingly engaging the first rod portion that abuts against the rodpositioner assembly to block rotation of the first rod portion and asecond position permitting rotation of the first rod portion, that thesecond means includes fourth means for mounting the live center memberfor rotation about said longitudinal axis, a housing, fifth meansrotatably mounting the fourth means in a longitudinally fixed positionin the housing, said fifth means being rotatably mounted by the housing,sixth means mounting the housing for longitudinal movement on the frame,said fifth means including seventh means for releasably clampinglyholding the adjacent end of the second rod portion, and eighth means fordrivingly rotating the fifth means, including the seventh means, aboutthe longitudinal axis, and that there is provided control means foractuating the seventh means to clampingly hold the second rod portion,and the eighth means to rotate the fifth means for a selected intervalwhen the seventh means clampingly holds the second rod portion andoperate the third means to its first position before the eighth meansrotates the fifth means and after the selected interval operate thethird means to its second position.
 12. The apparatus of claim 11further characterized in that there is provided operable ninth means onthe frame for longitudinally moving the sixth means between a firstposition remote from the first end portion and a second position moreclosely adjacent the first end portion and that the control meansincludes means for actuating the ninth means to move the sixth meansbetween its positions and to permit floating longitudinal movement ofthe sixth means when the seventh means clampingly holds the adjacent endof the second rod portion.
 13. The apparatus of claim 11 furthercharacterized in that the third means includes a first roller, a secondroller, ninth means for mounting said rollers for rotation abouttransverse axes sufficiently spaced to have the first rod portion on thecradle assembly extend therebetween the relatively move said rollersbetween a spaced apart non-clamping first position and a rod clampingsecond position to block rotation of the first rod portion clampedthereby, a third portion to move the first rod portion axially towardthe second end portion, and tenth means for drivingly rotating at leastone of the rollers in a direction to move the first rod portion towardthe frame second end portion, and that the control means includes meansfor actuating the tenth means when the rod hold down assembly is in itsfirst position.
 14. The apparatus of claim 11 further characterized inthat the rod positioner assembly includes a live center member abuttableagainst the first rod portion second end, ninth means for mounting thelive center member for rotation about said longitudinally axis in afixed longitudinal position relative thereto, and tenth means mounted onthe frame for moving the ninth means longitudinally between said rodpositioner assembly first and second positions.
 15. The apparatus ofclaim 14 wherein the first rod portion is tubular and has a frustoconical surface at its second end that is tapered radially outwardlytoward its first end and that the live center member has a frustoconical surface partially extendable into the first rod portion secondend to aid in properly aligning the first rod portion relative saidlongitudinal axis.
 16. The apparatus of Claim 11 further characterizedin that the cradle assembly includes a plurality of rollers assembliesmounted on the frame intermediate portion in longitudinally spacedrelationship for supporting the rod portions in longitudinal alignment,each roller assembly including a first roller, a second roller and ninthmeans for mounting the rollers longitudinally offset from one anotherfor rotation about longitudinal axes that are sufficiently spaced toprovide a nip to support the adjacent part of the respective rodportion.
 17. The apparatus of claim 16 further characterized in that therod hold down assembly includes a longitudinally elongated shaft, asubframe mounting said shaft for rotation about a longitudinal axis,said subframe being mounted on the frame intermediate portion formovement between a datum first position and a second position that theshaft is directly above roller assembly nips and more closely adjacentthe roller assemblies than the last mentioned first position, aplurality of hold down rollers keyed on said shaft in longitudinalspaced relationship for abutting against rod portions on the cradleassembly when the subframe is in its second position, means connected tosaid shaft for driving said shaft, and means mounted on the frame formoving the subframe between its positions.
 18. The apparatus of claim 17further characterized in that the rod hold down assembly includes rollermeans mounted on the subframe for bearing against the hold down rollersgenerally on the opposite side of the roller means from the rod portionson the cradle assembly when the subframe is in its second position, andthat there is provided one of said roller assemblies for each of thehold down rollers that is vertical below the respective hold down rollerwhen the subframe is in its second position.
 19. The apparatus of claim16 wherein the second rod portion comprises a pin and a box havingmatching thread portions and opposite end portions, one of said oppositeend portions having said second rod portion first end and an elongatedthird rod portion, that one of said roller assemblies comprises aplurality of said first rollers and a plurality of second rollers andthat the ninth means includes a base, means for mounting the base on theframe and resiliently urging the base upwardly to a datum position andmeans for mounting said plurality of first and second rollers on thebase, said one roller assembly being provided for supporting the pin andbox in a threaded connected position intermediate the first and thirdrod portions.
 20. The apparatus of claim 19 further characterized inthat the third means is mounted on the frame longitudinally intermediatethe rod positioner assembly and the said one roller assembly, that thethird means includes a driver roller abuttable against the first rodportion, eleventh means on the frame movable between a datum positionand a second position to hold the first rod portion in drivenrelationship to the drive roller, and twelfth means for driving thedriven roller in a direction to move the first rod portion toward thesecond end portion, and that the control means includes means foractuating the twelfth means to drive the drive roller and the eleventhmeans to its second position when the third means is in its firstposition.
 21. The apparatus of claim 11 further characterized in thatthere is provided ninth means on the frame intermediate portion forclampingly holding the first rod portion at a location remote from therod positioner assembly at the time the first rod portion abuts againstthe rod positioner assembly to prevent longitudinal movement thereof andalternately moving the first rod portion longitudinally toward the framesecond end portion.
 22. The apparatus of claim 21 further characterizedin that the ninth means includes a pair of rollers, tenth means formounting the rollers on circumferentially opposite sides of the firstrod portion when the first rod portion abuts against the rod positionerassembly, tenth Means mounting said rollers for rotation abouttransverse axes, and operable eleventh means for driving at least one ofsaid rollers in a direction to move the first rod portion toward thesecond end portion.
 23. The apparatus of claim 22 further characterizedin that the tenth means includes twelfth means for moving the rollersrelative one another between a datum spread apart position freelypermitting the first rod portion being moved longitudinallytherebetween, a second position to drivingly engage the first rodportion to move it longitudinally when the eleventh means is operated,and a third position to clampingly hold the first rod portion againstrotation about said longitudinal axis.
 24. The apparatus of claim 23further characterized in that the control means includes means foroperating the rod positioner assembly toward the chuck assembly whilemaintaining the twelfth means in its first position, automaticallyoperate the twelfth means from its first position to its third positionafter the rod portions have been welded together and thereafter operatethe twelfth means to its second position and operate the eleventh means.25. The apparatus of claim 24 wherein the second rod portion has athreadedly coupled pin and box adjacent its first end, furthercharacterized in that the control means includes means to operate theseventh means to its clamping position and the eighth means to drive thefifth and seventh means when the twelfth means is in its third positionto separate the threaded connection between the pin and box.
 26. Theapparatus of claim 23 further characterized in that there is providedoperable thirteenth means for moving the sixth means between a firstposition remote from the rod positioner assembly and a second positionmore closely adjacent the rod positioner assembly and that the controlmeans includes means for operating the thirteenth means to move thesixth means towards its first position prior to the rod portions beingwelded, to permit free floating longitudinal movement of the sixth meanswhen the pin and box are being separated as mentioned above, and afterthe separation, move the sixth means toward its second position whileretaining the seventh means in its clamping position.
 27. Rod weldingapparatus for welding the first end of a threaded pin and boxcombination to the first end of a first rod portion and the oppositesecond end of said combination to the first end of a second rod portion,each rod portion having an opposite second end, comprising alongitudinally elongated frame having a first end portion, anintermediate portion and a second end portion, first, second and thirdmeans mounted on the frame for supporting the first rod portion, saidcombination and the second rod portion respectively for rotation about acommon longitudinal axis with said combination between the rod portionsfirst ends, a chuck assembly mounted on the second end portion forabutting against the second rod portion adjacent its second end to blockmovement of the second rod portion in a longitudinal direction away fromthe first end portion, a rod positioner assembly mounted on the firstend portion for abutting against the first rod portion adjacent itsfirst end to act in cooperation with the chuck assembly for releasablyretaining the combination and rod portions in compression, fourth meansmounted on the frame for cooperating with the above mentioned means forretaining the combination and the rod portions in abutting compressionrelationship, and fifth means for welding the first rod portion firstend to the combination first end and the second rod portion first end tothe combination second end.
 28. The apparatus of claim 27 furthercharacterized in that the rod positioner assembly includes meansrotatable about the longitudinal axis for abutting against the first rodportion second end, that the fourth means includes a chuck assemblyhaving sixth means rotatable about the longitudinal axis for abuttingagainst the second rod pOrtion adjacent its second end, and that thereis provided seventh means for abutting against the rod portions to actin cooperation with the first and third means to retain the rod portionsin axial alignment and rotate said rod portions when the rod portionsare being welded to said combination.
 29. The apparatus of claim 27further characterized in that there is provided sixth means on the framefor clampingly holding the first rod portion against rotation about thelongitudinal axis after said rod portions have been welded to saidcombination and that the fourth means includes rotatable seventh meansfor clampingly engaging the second rod portion to rotate after the rodportions have been welded to the combination and eighth means mounted onthe frame for rotating the seventh means in a direction to disconnectthe pin and box threaded connection and mount the seventh means on theframe for longitudinal movement relative the rod positioner assembly ina direction away from the rod positioner assembly as the seventh meansis rotated.
 30. The apparatus of claim 29 further characterized in thatthe eighth means includes a chuck member for clampingly engaging thesecond rod portion, a base, ninth means mounting the chuck member on thebase in a fixed longitudinal position relative the base and mounting thechuck member for rotation relative the base, tenth means connected tothe chuck member to rotate the chuck member to threadedly disconnect thepin and box, and means for mounting the base on the frame forlongitudinal movement.
 31. The apparatus of claim 30 furthercharacterized in that there is provided operable means for moving thebase between a first position and a second position more longitudinallyremote from the rod positioner assembly than the last mentioned firstposition and control means for operating said operable means to a floatcondition intermediate the operable means first and second positionsafter the rod portions have been welded to the combination and retainthe float condition while the pin and box are being threadedlydisconnected and thereafter operate the operable means toward its secondposition while the chuck member clampingly engages the second rodportion to more remotely space the pin and box.
 32. Rod weldingapparatus for welding the first end of a first axially elongated rodportion to a first end of a second axially elongated rod portion, eachof said rod portions having a second end, comprising a longitudinallyelongated frame having a first end portion, an intermediate portion anda second end portion, rod hold down and cradle assembly means mounted onthe frame and operable between a first condition for supporting the rodportions in longitudinally extending, axially aligned relationship and asecond condition for holding the rod portions in fixed transversepositions and rotating the rod portions in axial alignment about theirlongitudinal axes, said hold down and cradle assembly means including acradle assembly mounted on the frame for supporting the rod portions inlongitudinally extending, axially aligned relationship with the firstrod portion extending adjacent the first end portion and the second rodportion extending adjacent the second end portion, and a hold downassembly for holding the rod portions in fixed transverse positions onthe cradle assembly while permitting rotation of the rod portions aboutsaid longitudinal axes, said hold down assembly being mounted on theintermediate portion for movement between a datum first position out ofengagement with the rod portions on the cradle assembly and a rod holddown second position cooperating with the cradle assembly to hold therod portions in fixed transverse positions and rotate the rod portions,a chuck assembly mounted on the second end portion for engaging theadjacent end portion of the second rod portion to retain the second rodportion against movement in a longitudinal direction from the first endportion toward the second end portion for a first interval of tIme whenpermitting rotation of the second rod portion about a longitudinal axisof the rod portions supported on the cradle assembly, a rod positionerassembly mounted on the first end portion for longitudinal movementbetween a datum first position and a second position abutting againstthe second end of the first rod portion to retain the first end of thefirst rod portion against the first end of the second rod portion thatis remote from the chuck assembly when the second rod portion is engagedthereby, and welding means for welding the rod portions to join said rodportions first ends together as the rod portions are being rotated bythe hold down and cradle assembly means and the rod portions extend onthe cradle assembly between the rod positioner assembly in its secondposition and the chuck assembly and the second rod portion abuts againstthe chuck assembly during said first interval of time.